The present invention relates to an air conditioner for a vehicle and, more particularly, to a peripheral construction of a fan of a centrifugal blower for an air conditioner.
A centrifugal blower has been mainly used in an air conditioner for a vehicle to condition the indoor air of the vehicle. A fan of the centrifugal blower is ordinarily rotated by a motor to take in air from one side of a rotational shaft and to exhaust the air in a circumferential direction. The air taken in is normally fresh atmospheric air from outside of the vehicle. When the blowing air quantity increases to a predetermined value or higher, the fan takes in and exhausts recirculated air from the compartment of the vehicle. The prior technique for constructing an air intake port of a conventional air conditioner for the vehicle is disclosed, for example, in Japanese Utility Model Application Laid-open No. 65109/83. This prior art forms an air intake box body in a dome shape so as to smoothly switch the intakes of fresh air and recirculated air and provides a fresh atmospheric air intake port at the dome.
However, the effective air intake volume cannot be altered in the abovementioned prior art and other conventional techniques even if the construction of the periphery of the air intake port of an air intake box body is devised in any way. Thus, if the blowing air quantity must be increased to the maximum, the prior art cannot obtain sufficient air intake volume, thereby reducing the efficiency of the blower, increasing the power consumption and preventing sufficient air blowing quantity.